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<title>Stereotype Mode</title>
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<h1>Stereotype Mode</h1>
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<pre>In Stereotype Mode, the server offers support for stereotypes.
Stereotypes are categories of users with specific characteristics.
Each stereotype has a profile that is defined by means of (feature,
value) tupples. Features can be entities relevant to specific
applications, while values give an estimation about the stereotype
relevence to corresponding features. Each stereotype may have
its own different features. Features can be organized in a
tree or graph based manner, for easily managing conceptual
hierarchies. This organization is encoded in the name of every
feature as a path expression, and is setup by applications.
Users can be assigned stereotypes, together with a degree of
relevence, showing how relevent is a stereotype to a user.
A user may be assigned several stereotypes (not the same twice).
The DB structure: stereotypes (st_stereotype) with key 'st_stereotype',
stereotype_profiles (sp_stereotype, sp_feature, sp_value, sp_numvalue)
with key 'sp_stereotype' and 'sp_feature', stereotype_users
(su_user, su_stereotype, su_degree) with key 'su_user' and
'su_stereotype'. If a field in 'stereotypes' is deleted, the deletion
is cascaded to 'stereotype_profiles' and 'stereotype_users', because
of referential integrity constraints. The field 'sp_numvalue' is
&quot;invisible&quot;: it is not part of the results of 'select' queries,
and contains the numeric equivalent of the string value in field
'sp_value', or NULL if the string cannot be converted to numeric.
This duplicate field is used mainly to allow for two types of value
comparisons: string and numeric. Note that the primary data type for
values is always string, as it is more general, and that the numeric
version always correspond to the string version. Also note that
values intented to be numeric must use '.' for the decimal part when
given as strings. If ',' is used, the string will not be successfully
converted to numeric, and its numeric equivalent will be NULL. The
field 'su_degree' is numeric (double), and when its values are
exchanged as strings they follow the rules described above. This
field also contain NULLs for values that could not be converted to
numeric.
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